
"""simple docstring"""



def lowerCamelCase_				(     _lowerCamelCase			:	Optional[int]				):
       return credit_card_number.startswith(('''34''', '''35''', '''37''', '''4''', '''5''', '''6''')				)


def lowerCamelCase_				(     _lowerCamelCase			:	int				):
       lowerCamelCase_       							=		credit_card_number
       lowerCamelCase_       							=		0
       lowerCamelCase_       							=		len(snake_case__				) - 2
       for i in range(snake_case__					,				-1					,				-2				):
              #  double the value of every second digit
              lowerCamelCase_       							=		int(cc_number[i]				)
              digit *= 2
              # If doubling of a number results in a two digit number
              # i.e greater than 9(e.g., 6 × 2 = 12),
              # then add the digits of the product (e.g., 12: 1 + 2 = 3, 15: 1 + 5 = 6),
              # to get a single digit number.
              if digit > 9:
                     digit %= 1_0
                     digit += 1
              lowerCamelCase_       							=		cc_number[:i] + str(snake_case__				) + cc_number[i + 1 :]
              total += digit

       # Sum up the remaining digits
       for i in range(len(snake_case__				) - 1					,				-1					,				-2				):
              total += int(cc_number[i]				)

       return total % 1_0 == 0


def lowerCamelCase_				(     _lowerCamelCase			:	Union[str, Any]				):
       lowerCamelCase_       							=		F"""{credit_card_number} is an invalid credit card number because"""
       if not credit_card_number.isdigit():
              print(F"""{error_message} it has nonnumerical characters."""				)
              return False

       if not 1_3 <= len(snake_case__				) <= 1_6:
              print(F"""{error_message} of its length."""				)
              return False

       if not validate_initial_digits(snake_case__				):
              print(F"""{error_message} of its first two digits."""				)
              return False

       if not luhn_validation(snake_case__				):
              print(F"""{error_message} it fails the Luhn check."""				)
              return False

       print(F"""{credit_card_number} is a valid credit card number."""				)
       return True


if __name__ == "__main__":
 import doctest

 doctest.testmod()
 validate_credit_card_number("""4111111111111111""")
 validate_credit_card_number("""32323""")





"""simple docstring"""




from collections.abc import Sequence



def        a__					(							snake_case__			,					snake_case__ = False							)		->   float:
			if not arr:
						return 0

			lowerCamelCase      =   0 if allow_empty_subarrays else float("""-inf"""							)
			lowerCamelCase      =   0.0
			for num in arr:
						lowerCamelCase      =   max(0 if allow_empty_subarrays else num			,					curr_sum + num							)
						lowerCamelCase      =   max(snake_case__			,					snake_case__							)

			return max_sum


if __name__ == "__main__":
					from doctest import testmod

					testmod()

					lowerCAmelCase				:     Union[str, Any]					=				[-2, 1, -3, 4, -1, 2, 1, -5, 4]
					print(F"""{max_subarray_sum(nums) = }""")



